Process for the treatment of leather of like material



H. S. POCHIN Feb. 27, 1934.

PROCESS FOR THE TREATMENT OF LEATHER 0R LIKE MATERIAL Filed May 28, 1952 2 Sheets-Sheet l "Aim "ni I n I I l #Z 5. Vac

H. S. POCHIN Feb. 27, 1934.

PROCESS FOR THE TREATMENT OF LEATHER OR LIKE MATERIAL Filed May 28, 1952 2 Sheets-Sheet 2 Patented Feb. 27, 1934 PROCESS FOR THE TREATMENT OF LEATHER 0R LIKE MATERIAL Horace Stanley Pochin, Leicester, England Application May 28, 1932, Serial No. 614,236 In Great Britain June 16, 1931 1 Claim.

This invention relates to the treatment of leather particularly for soles and stiffeners ior footwear, it being understood, however, that the invention is applicable to leather for other purposes or other material in connection with which what is known as a tempering treatment is necessary or desirable.

In the tempering of leather for soles and stiffeners for example it has hitherto been usual to soak the leather in a tank of water for a period varying from one to twelve hours according to the substance and texture after which the leather is allowed to drain for approximately one hour and is then placed in a cupboard or tempering cabinet for a period varying from approximately eight to twelve hours. Moreover, when the soles or stiffeners are required to be solutioned it has been the custom to apply the solution to the soles before the soaking operation since it is not desirable to put solution on wet leather.

The object of the present invention is to reduce very considerably the time taken by the tempering operation so as largely to increase output and materially assist in the organization of the factory. Another very important advantage of the process in accordance with the invention is that only clean water comes into contact with the soles, stifieners or other material with the result that they are not liable to become stained and further, after the process of tempering, it is not necessary to allow any length of time to elapse before the footwear is ready for finishing (as is the case with ordinary tempering processes) for the reason that the material dries very much more quickly after being tempered in accordance with the invention. The invention consists in a process for tempering leather and like material which comprises treating the material with water or liquid while under vacuum or reduced pressure.

The apparatus for carrying out the above process comprises a cabinet or container in which the leather soles or other material may be supported and having water or liquids there in, means for immersing said soles or material in the water or liquid, and means for establishing a vacuum in the interior of the container.

The apparatus of the above character involves racks for the support of the material within the container and means for lowering said racks to immerse the soles or material in the water or liquid in the container.

Further features of the invention will be apparent from the description given hereafter.

The accompanying drawings illustrate severa modes of carrying out the invention.

Figure 1 is an elevation of one form oi apparatus.

Figure 2 is a cross-sectional elevation 0 Figure 1. Figure 3 is an elevation of a further form of apparatus, and

Figure 4 is a view showing a modification of the apparatus shown in Figure 3.

In carrying my invention into effect in one convenient manner as illustrated in Figure 1, I form my improved apparatus with a tempering cabinet or container a 01' suitable size and shape and conveniently constructed so as to be airtight when closed, the interior of the cabinet being in communication with a suitable vacuum pump 2) or other exhausting device and being conveniently fitted with a vacuum gauge c'to indicate the de: gree of vacuum within the container.

In the iioor of the container or in any other suitable position therein I arrange two or other, convenient number of atomizers d eachconnected to a supply of water under pressure, the spraydevices being such that they will spray simultaneous- 1y both sides of the leather soles e inserted in the tempering chamber and which for the purpose are conveniently arranged in racks f of helically coiled wire or other suitable devices by which the water spray may have full access to both sides of the leather. In the upper part of the tempering. cabinet there is an air cock 9 which may be opened for the purpose of allowing the water to drain from the tempering cabinet by a suitable drain it regulated by means of a valve i provided for the purpose.

In operation the operator would conveniently be provided with a number of racks, each of which is adapted to hold a plurality of leather soles so that the operator can be preparing racks of soles for treatment while the tempering process is be-- ing carried on. The soles to be treated having been inserted in the cabinet and the latter closed in an airtight manner, the interior is exhausted until the vacuum gauge shows a vacuum of say 25 inches of mercury whereupon the exhausting operation is discontinued and the water sprays turned on so that the leather soles are thoroughly wetted while under a vacuum, the object of which is to withdraw the air from the pores or interstices in the leather thus enabling the material immediately to absorb the water from the sprays. The spraying operation is continued for say two or three minutes when the water supply is turned off and. the drain and air inlet opened for the purpose of emptying the water from the container. The soles are then taken out and another tray of soles put in so that the above operation may be repeated on a new supply and those soles which have been taken out are allowed to temper for about ten minutes or in some cases the drying may be assisted by a hot air blast.

The whole operation will thus take little more than approximately ten to thirty minutes as compared with a period of eight to twelve hours under the old system and the increase in output and the assistance to the organization of the factory by this saving of time will be readily appreciated.

In the modified form of apparatus shown in Figure 3, I dispense with the atomizers and insert water or other liquid up to a determined level within the container at, and if desired any convenient means may be adopted for maintaining the level constant.

The soles or other articles (either cemented or not) are conveniently arranged in racks of helically coiled wire or other suitable devices so that the whole of the soles or the like may be thoroughly immersed in the liquid and be brought intimately into contact therewith, and the container may be fitted with inlet and outlet valves is k to enable the water or liquid to be changed at intervals.

The racks or trays f may be supported in a suitable cage l which may be moved up and down by hand lever Z or other operative mechanism, a counterweight m being employed, if desired, to assist or facilitate the raising and lowering operation.

In operation the operator would conveniently be provided with a number of racks, each of which is adapted to hold a plurality of leather soles so that the operator can be preparing racks of soles for treatment while the tempering process is being carried on. The soles to be treated having been inserted in the cabinet and the latter closed in an airtight manner, the interior is exhausted until the vacuum gauge shows a vacuum of, say, 23 inches to 25 inches of mercury whereupon the exhausting operation is discontinued and the cage lowered so that the leather soles are thoroughly immersed and wetted while under a vacuum, the object of which is to withdraw the air from the pores or interstices in the leather thus enabling the material immediately to absorb. the water or liquid. The vacuum may be broken (as by an air valve 9) immediately after immersion and the latter is continued for, say, 10- or 15 minutes according to substance and tannage. During the period of immersion the vacuum is again established (valve g being closed) and when the soles are lifted from the water the vacuum is gradually broken by partly opening airvalve g and by this means all surface liquid is removed from the leather or material.

The chamber is opened and the trays 3" (which may be provided with pegs f to hold the soles from contact with each other) removed and passed to the sole attacher.

Among the advantages obtained by the invention may be mentioned the following:-

1. The soles are tempered, freed from surface moisture and ready for use within'about thirty minutes.

2. The chemicals in the leather are not removed as in the old tank system, as the soles are only in water ten minutes.

3. The soles are not stacked wet under this system and the loss through stained soles is thus avoided.

4. There is less handling of the soles, resulting in saving of time and money; the soles are put into the tray as solutioned, and (after leaving the tempering cabinet) are only taken out by the sole attacher.

If desired two or any number of chambers may be provided in association with one another and in any modification of the invention I may break the vacuum once only (either during or after immersion) instead of twice as above described.

In some cases I may subject the material to. pressure as well as to vacuum, a convenient form of apparatus for this purpose being shown in Figure 4. The apparatus is similar to the foregoing, but I provide the pump b with additional piping n and fit two three-way valves 0 o. as shown. These valves are fitted with L ports and assembled in such a way that when both handles are in the full-line position the pump operates as an exhauster, while in the dotted position of the handles the pump operates as a com-.

pressor.

The application of pressure during the immersion is particularly advantageous with harder leathers and with leathers of which the pores are filled with solid matter.

The invention is not to be limited to the foregoing details of construction which are. given by way of illustration only as I may vary the nature of the treating liquid, the means for supporting the material to be treated within the tempering cabinet and the degree of exhaust provided depending upon the character of the material to be treated or any practical requirements to be fulfilled.

Having now described my invention, what I claim as new and desire to secure by Letters Patent isz- A process for the tempering of leather which comprises subjecting the leather to vacuum and immersing the same in water while under vacuum, breaking the vacuum during immersion and subsequently re-establishing the vacuum. before immersion is completed and finally withdrawing the leather from the water and gradually breaking the vacuum.

HORACE STANLEY POCHIN.

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